Flip heightmap's Y position on Ogre 2 and add sanity checks for NaN

Changelog.md

@@ -10,7 +10,7 @@
 1. Increase particle emitter quota
     * [Pull request #562](https://github.com/ignitionrobotics/ign-rendering/pull/562)
 
-1.Make sure shader param exists before setting its value
+1. Make sure shader param exists before setting its value
     * [Pull request #558](https://github.com/ignitionrobotics/ign-rendering/pull/558)
 
 1. Backport wave changes

Migration.md

@@ -5,6 +5,18 @@ Deprecated code produces compile-time warnings. These warning serve as
 notification to users that their code should be upgraded. The next major
 release will remove the deprecated code.
 
+## Ignition Rendering 6.2.1 to 6.X
+
+### Modifications
+
+1. Ogre 2 heightmaps: the Y position sign was flipped
+
+1. `Scene::SetTime` is often unset. Ignition's `Ogre2` now defaults to 60hz otherwise rendering won't advance forward.
+	+ Mostly affects Particles.
+	+ Also may affect gaussian postprocessing and other filters dependant on time.
+	+ Previous behavior was using real time instead of simulation time, which is wrong.
+	+ See https://github.com/ignitionrobotics/ign-rendering/issues/556 for details.
+
 ## Ignition Rendering 5.x to 6.x
 
 ### Modifications
@@ -40,12 +52,6 @@ release will remove the deprecated code.
 1. **depth_camera_fs.glsl** and **depth_camera_final_fs.glsl**
     + Far clipping changed from clipping by depth to clipping by range, i.e. distance to point, so that the data generated will never exceed the specified max range of the camera.
 
-1. `Scene::SetTime` is often unset. Ignition's `Ogre2` now defaults to 60hz otherwise rendering won't advance forward.
-	+ Mostly affects Particles.
-	+ Also may affect gaussian postprocessing and other filters dependant on time.
-	+ Previous behavior was using real time instead of simulation time, which is wrong.
-	+ See https://github.com/ignitionrobotics/ign-rendering/issues/556 for details.
-
 ## Ignition Rendering 4.0 to 4.1
 
 ## ABI break

examples/heightmap/Main.cc

@@ -152,7 +152,7 @@ void buildScene(ScenePtr _scene)
   textureC2.SetDiffuse("../media/dirt_diffusespecular.png");
   textureC2.SetNormal("../media/flat_normal.png");
   desc2.AddTexture(textureC2);
-  desc2.SetPosition({30, 0, 0});
+  desc2.SetPosition({30, 10, 0});
   auto heightmapGeom2 = _scene->CreateHeightmap(desc2);
 
   auto vis2 = _scene->CreateVisual();

ogre/src/OgreHeightmap.cc

@@ -491,7 +491,14 @@ void OgreHeightmap::Init()
     for (unsigned int x = 0; x < vertSize; ++x)
     {
       int index = (vertSize - y - 1) * vertSize + x;
-      this->dataPtr->heights.push_back(lookup[index] - minElevation);
+
+      // Sanity check in case we get NaNs from ign-common, this prevents a crash
+      // in Ogre
+      auto value = lookup[index];
+      if (!std::isfinite(value))
+        value = minElevation;
+
+      this->dataPtr->heights.push_back(value - minElevation);
     }
   }
 

ogre2/src/Ogre2Heightmap.cc

@@ -166,7 +166,13 @@ void Ogre2Heightmap::Init()
     for (unsigned int x = 0; x < newWidth; ++x)
     {
       const size_t index = y * srcWidth + x;
-      const float heightVal = lookup[index];
+      float heightVal = lookup[index];
+
+      // Sanity check in case we get NaNs from ign-common, this prevents a crash
+      // in Ogre
+      if (!std::isfinite(heightVal))
+        heightVal = minElevation;
+
       minElevation = std::min(minElevation, heightVal);
       maxElevation = std::max(maxElevation, heightVal);
       this->dataPtr->heights.push_back(heightVal);
@@ -208,9 +214,10 @@ void Ogre2Heightmap::Init()
   const math::Vector3d newSize = this->descriptor.Size() *
                                  math::Vector3d(1.0, 1.0, heightDiff);
 
+  // The position's Y sign ends up flipped
   math::Vector3d center(
       this->descriptor.Position().X(),
-      this->descriptor.Position().Y(),
+      -this->descriptor.Position().Y(),
       this->descriptor.Position().Z() + newSize.Z() * 0.5 + minElevation);
 
   Ogre::Root *ogreRoot = Ogre2RenderEngine::Instance()->OgreRoot();